TiN drill bits

I have some TiN bits and I have been happy with them. They cut quickly and cleanly. There was a recent post on the forum stating that with this type of bit, you need to avoid excessive pressure and let the bit cut on its own with just enough pressure to keep the bit moving. According to the poster, the coating is somewhat brittle and can flake off the cutting surface if too much pressure is applied. I don't have enough experience to endorse or refute this claim, but it is consistent with what I know about physics and materials science. 

 

Bosch certainly has an excellent reputation. I don't have any of their TiN bits but I have a few Bosch power tools and router bits and they are first rate. You might want to look on Amazon.com for buyer reviews on bit sets, and for a good price on Bosch. 

Hiawatha is right. Great bits, but as with all drill bits, take your time and let the bit itself do the work, don't force it through, especially if you're using these with steel. Some cutting oil goes a long long way.

It depends on the materials you will be drilling, and the frequency that the drills will be used. Unless you are planning to drill stainless and alloy metals, the TiN (and other coated) bits are an expensive luxury, costing double to triple. For around the house and general hobby use, polished finish, split point drill bits will suffice. For better wear resistance, you may wish to consider cobalt drill bits; more costly than plain high speed steel, but cheaper than coated bits. The only coated tools I use are milling cutters because they take a beating and are expensive to replace, so the coatings pay for themselves. Check out MSC Industrial and McMaster Carr for what is available and pricing. They both carry top brands. Of course if Santa Claus has extremely deep pockets, than coated carbide would be the ultimate.

 

Larry

The high tech bits I save for high tech metals. I have the better "Drill Doctor" to sharpen my non coated, old fashioned bits. Broke or dull I fix-um. Does an anti-walk split back cut tip too. It has paid for itself many times over, and I will buy one again immediately if it dies.

Number and letter sets together as one, are my preference. Though really large, actually often a bang for the buck. I normally check with a local contractor/industrial supply houses(heat&AC, plumbing, electric, etc), Grainger, or even Harbor Freight for deals on machining stuff, rather than the local big box hardware.  

I have one of those full sets of bits including fractional, wire gauge (number) and letter bits.
I don't think I have ever used the letter bits.

I use the wire gauge bits (number) very frequently, probably as often as the fractional.

 

This time of year many stores will have fractional drill bit sets on sale with deep discounts. Common sources are Ace Hardware, Lowes, and Home Depot. Over the years I've stocked up.

 

 

 

I don't know about the angle of the bit cut, but I use the two sets below (both bought through Amazon).  The Steelex Plus D1138 HSS Tin Dill set (left) is a great set, which I got on Amazon for around $55 meets all your criteria except the reduced 3/8 inch shank. With 115 bits it always has a size for everything from 1/16 to 1/2.  I've used it to cut mild steel, wood , plastic, composites, etc.  About $55.  The wood case, about $37 normally, has five bits in each of 20 sizes from .3 mm to 1.6 mm, all suitable for a pin vise which I use for fine work.  I've never used these on anything but wood or plastic.  

 

I am a big believer in not buying expensive drill bits (or saw blades) or trying to resharpen old bits (my experience is they walk a lot more thereafter).  I view them as disposeable units. I don't buy the cheapest, but these are examples of great value.  I've never had one go dull but some of the small ones do break from time to time and I tend, despite taking some care, to lose the odd bit from time to time.  So I just buy a new set when they are on sale about ever two years and chuck (pun intended) the old one (I recently got a new set of 115 pieces for $23!!) and just renew the entire set. 

 

I have many types and kinds of bits in sizes up to 35mm. they all get dull after a few uses, no exceptions, even carbide masonary bits. a decent bench grinder with a fine grit wheel and a diamond wheel and about 2 hours of practice and you can master sharpening. the key is sharpening, take the time to learn and you will be very happy with the results.

Cutting oil goes a long ways in extending the life of any drill bit, heat is the enemy.  I agree with the previous John, you can eventually dull them.  I bought a large box of multiples of every size, and when one gets dull, I just replace it.  I figure the box will last my lifetime.

 

Sharping the Titanium bits is possible, but they're no longer Titanium as it's only a coating.

 

Been a custom fabricator for 30plus years.
Every new guy starts off with a complete set of number, letter and fraction bits in a long metal box.
Guaranteed in a few years that same guy is missing the E (.250) the 7, 21, and a few other of the common tap and clearance hole bits.
Usually they will have litle bulk pack engel elopes of these sizes in the drawer. Use them till they are dull and toss them.
Then the never go back to the set unless they run out and can substitute the next size till they reorder.

Specialty bits are best used in controlled production environments with the proper coolants, spindle speeds and feed rates.

Using good old HSS bits, either you get the feel for them quickly, or you get frustrated and stop doing your own work.
Just MHO

Exactly how I handle them, when they get dull, I pull out a new replacement and the dull one goes into the bin.  I'm sure I could learn to sharpen them, but life's too short to spend time doing that.

 

 

quote:

Guaranteed in a few years that same guy is missing the E (.250) the 7, 21, and a few other of the common tap and clearance hole bits.
Usually they will have litle bulk pack engel elopes of these sizes in the drawer. Use them till they are dull and toss them.
Then the never go back to the set unless they run out and can substitute the next size till they reorder.

 

Largely true. I've purchased bulk packs of the ones I've dulled or broken.

I also use my drill bits for two other purposes:

 

I will hold a bit in my hand, or in a pin vise, and use the bit to clean out holes were necessary. One example would be the rollers on a 364 log loader. Those rollers need to turn freely. I find a bit that just fits. Don't want to enlarge the hole, just clean it.

 

I have also used the shanks of my drill bits to try to get a good approximation of the diameter of a hole. I find the smallest bit that is too large and the largest bit that fits to estimate the hole size.

To me the bottom line is that drill bits - at least good enough quality drill bits, are cheap.  The115 piece set I posted a photo of above, bought on sale, is around 35 cents per bit.  For that cost, its not worth fussing with trying to sharpen, etc.: I view them as commodity, disposable units: wear them out of lose them and just replace when needed.  

 

I also used them for other applications.  Yesterday I needed to add some weight to a seven-inch long box trailer I had scratch build for a 1:50 'Sctreets big-rig.  I just picked out three big (roughly 3/8 inch) drill bits in sizes I probably will not need soon, each about 6 inches long and dropped them in the trailer.  They worked so well I went ahead and epoxied them into it as permanent weights.  Not what they were intended for, but they worked so well . . . 

Here's a photo of very small bits, brand new out of the box.  It's good practice to check the bit before applying it to your handiwork.  (Model Expo = junk)

 

 

Using good old HSS bits, either you get the feel for them quickly, or you get frustrated and stop doing your own work. 

 

 

I agree, its good quality high speed bits for me.  

 

Bill

Well, I do shop at Model Expo for model shipbuilding wood, etc., but not tools.  I've had similar experiences.  Ugh.

A buddy of mine who is an amateur gunsmith taught me a neat use for dull or broken drill bits. Cut to length, they make great super-hard pivot or fixing pins for various applications (mainly in guns, but elsewhere as well). 

Wow, great discussion here.  My concern was that they would work for metal but wood or plastic would dull them.  Appears that a good set should be just fine for my around the house and layout light metal and wood purposes.

If you drill in brass, you need zero rake drills.  I have no idea where one buys them, but I have become proficient with a Dremel cut- off disc and a magnifying light.

 

I have found that drilling in zamak can present the sams sorts of problems, so I use zero rake drills there, too.  The HSS drills are designed for mild steel, a material found only in rare places on model trains.

 

I find a good center punch and pilot hole, all done with magnification, aid in good concentric accurately located holes.  I also find that a good drill press is simply required.

 

This is all opinion, but you should know I build my own locomotives out of brass.  If you are drilling anything larger than a #43 hole, the zero rake is a safety consideration - you can get hurt when a regular drill bit bites into brass and starts flinging it around the work area.

bob2:

 

Thanks for the tip. That's a new one on me - I have occasionally had problems with drill bits grabbing in brass, but this is the first time I ever heard of a zero rake bit. I did some Googling and the only commercially made zero rake bits I could find were for Plexiglas and acrylic - they have 90 degree points and are not suited for metal. I did, however, find a nice how-to for modifying your own. Next time I have to drill brass I guess I'll have to get out a honing stone.